Madgets

Abstract

We present a system for the actuation of tangible magnetic widgets (Madgets) on interactive tabletops. Our system combines electromagnetic actuation with fiber optic tracking to move and operate physical controls. The presented mechanism supports actuating complex tangibles that consist of multiple parts. A grid of optical fibers transmits marker positions past our actuation hardware to cameras below the table. We introduce a visual tracking algorithm that is able to detect objects and touches from the strongly sub-sampled video input of that grid. Six sample Madgets illustrate the capabilities of our approach, ranging from tangential movement and height actuation to inductive power transfer. Madgets combine the benefits of passive, untethered, and translucent tangibles with the ability to actuate them with multiple degrees of freedom.